package com.hmdp.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * @author blh
 * @date 2024年06月14日 11:47
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private RedissonClient redissonClient;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result seckillVoucher(Long voucherId) {
        // 1 查询优惠卷
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        // 2 判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            // 尚未开始
            return Result.fail("秒杀尚未开始");
        }
        // 3 判断秒杀是否结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀已经结束");
        }
        // 4 判断库存是否充足
        if (voucher.getStock() < 1) {
            return Result.fail("库存不足");
        }
        Long userId = UserHolder.getUser().getId();

        // 创建锁对象
        // SimpleRedisLock simpleRedisLock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        RLock lock = redissonClient.getLock("order:" + userId);
        // 获取锁
        boolean isLock = lock.tryLock();
        // 判断是否获取锁成功
        if (!isLock){
            // 获取代理对象(事务)失败, 返回错误信息或重试
            return Result.fail("不允许重复下单");
        }
        try {
            // 获取代理对象
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        } finally {
            lock.unlock();
        }
    }

    @Transactional
    public Result createVoucherOrder(Long voucherId) {
        // 6 艺人一单的判断
        Long userId = UserHolder.getUser().getId();
        synchronized (userId.toString()) {
            // 查询订单
            Integer count = query()
                    .eq("user_id", userId)
                    .eq("voucher_id", voucherId)
                    .count();
            // 判断是否存在
            if (count > 0) {
                // 用户已经购买过了
                return Result.fail("已经购买过了");
            }

            // 5 扣减库存
            boolean success = seckillVoucherService.update()
                    .setSql("stock = stock - 1")
                    .eq("voucher_id", voucherId).gt("stock", 0)
                    .update();
            if (!success) {
                return Result.fail("库存不足");
            }

            // 6 创建订单
            VoucherOrder voucherOrder = new VoucherOrder();
            // 6.1 订单Id
            long orderId = redisIdWorker.nextId("order");
            voucherOrder.setId(orderId);
            // 6.2 用户Id

            voucherOrder.setUserId(userId);
            // 6.3 代金券Id
            voucherOrder.setVoucherId(voucherId);
            save(voucherOrder);
            return Result.ok(orderId);
        }
    }
}
